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​NETWORK RTK

A BRIEF HISTORY


​Single Base RTK
During the 1990’s GPS RTK surveying started to become a real benefit to users. The concept was based on two GPS receivers, known as a “Base and Rover”. The set of receivers measured distances to the satellites, using the L1 & L2 carrier phase signals. The base station transmits it’s known position to the rover via a UHF radio. The rover then uses the base station position, together with its common set of satellite observations, to solve ambiguities and precisely compute its position to cm level accuracy. However, like most first generation technology the kit was large in comparison to today, with many batteries, cables, poles, tripods, backpacks and other accessories to carry around and set-up.

There can also be distance dependent limitations to the “base rover” method, where the accuracy degrades the further the rover moves away from the base station. This is mainly caused by an increase in atmospheric errors between the base and rover, which makes it harder for the rover to fix its position.

In its early inception, for many GPS or GNSS surveying was deemed as a “black art” and a highly scientific method, where the operator needed a high level of education, or even a degree in GPS surveying!


​Traditional “base & rover” method of receiving RTK corrections. The base station is set-up on a known point and sends corrections to the rover, normally via a UHF radio link.
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Tradition Single Base RTK
Although the general method of setting up a base and rover is now well known, there are further disadvantages, such as;
  • The cost to purchase the base station, together with the rover.
  • Time needed to set-up the base station, or move it to a new location.
  • Security of the base station, if not fixed to a building or site cabin.
  • Post processing the results of the survey to national grid coordinates.
  • Radio link limitations and distance dependent errors, the further the rover is from the base station.
Network RTK
During the last decade a new method of Network RTK has evolved, and in the last five years it has matured as the de-facto standard for many GNSS applications.

​Network RTK is based on a set of Continuously Operating Reference Stations (CORS), which could form a national or regional reference station infrastructure. GNSS satellite observations are continuously gathered from all the reference stations, and streamed to a central processing centre via the internet. All the observations are then used to model the entire network, which is now free from the distance dependent constraints of a traditional base & rover. At Topcon we use the state-of-the-art network software called TopNET+.


Network RTK is based on a set of reference stations continuously streaming GNSS observations to a control centre (TopNET+).


The distances between the reference stations may be as large as 70km and could span an entire country.
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TopNet Live Network RTK
Network RTK Subscriptions
Many Network RTK subscription services now exist throughout Europe and the world, such as the TopNET live service. Network RTK rovers are now widely used with subscriptions, such as the Topcon GRS-1, GRS-3, AGI3 etc..
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Rover users working anywhere within the network boundary can connect to the TopNET live service (the TopNET+ server) via mobile internet connections (GSM, GPRS, 3G etc..) and will receive fully modelled Network RTK corrections.


There Are Many Advantages Of Network RTK, Such As:
  • No need to purchase a base station
  • No need to set-up and move a base station
  • No security issues to protect the base station
  • Modelled network corrections which provide a “constant” level of accuracy across the entire network coverage area
  • Increased productivity using two rovers compared to a base & rover set
  • All users are using a common coordinate system, normally linked directly to the national grid system
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There Are 4 Basic Steps To The Network Agency Management:

  • The Reference station infrastructure
  • TopNET Live Data Centre
  • Network Web Manager or MAGNET Enterprise
  • End users RTK Subscriptions

    Sign Up Now For A Free (No Obligation) 30 Day Trial

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360 E. International Airport RD. Suite 10 Anchorage, AK 99518
Office (907)562-8000
                ​Fax (907)562-8080
                 
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  • Home
  • Training & News
    • Training
    • News
  • Contact
    • Location
    • Staff
  • Construction
    • Machine Automation
    • GPS Surveying Systems
    • Field Controllers
    • Lasers, Levels, Laser Receivers, and Theodolites
    • Scales
    • Return On Investment
  • Survey
    • GPS Surveying Systems
    • Field Controllers
    • Levels
    • Total Stations and Theodolites
  • Mass Data Collection
    • Aerial Mapping
    • Mobile Mapping
    • Laser Scanning
  • Software
    • Construction Software
    • Survey Software
    • Mass Data & Mapping Software
    • Monitoring Software
  • TopNet Live